Thursday, 3 August 2017

Her Royal Majesty M22

Number 22 on Messier's list of astronomical objects is the third-brightest globular cluster in the sky and the brightest visible from northern latitudes. On a clear night it will already reveal itself to the naked eye in the heart of one of the most stunning stellar landscapes that the Universe grants us. It lies just south of the densest part of our Milky Way, with the Sagittarius Stellar Cloud and the immense Lagoon Nebula nearby.

M22's a fairly large globular cluster with its half a million stars, but nothing out of the ordinary. The reason why it's so bright is because it's one of the closest globulars, its distance estimated to be only 10,400 light-years. Considering that the centre of our galaxy lies more than twice as far away, that's pretty close. In any case, M22 certainly merits its reputation as one of the finest globular clusters as I hope my sketch illustrates.

Interesting to note is that recent investigations with the Hubble Space Telescope discovered a large number of planet-sized objects which appear to roam in this cluster without belonging to any particular star. It seems only logical that planets, which form at a certain distance from their parent star, get severely disturbed by the multitude of extremely close neighbour stars and as a result these planets are torn away, destined to float from one star to the other.